Various fluid ejection device arrangements, such as inkjet printheads, are known in the art and include thermally actuated drop ejection elements, which use resistive elements or the like to achieve fluid expulsion. For example, a representative thermal inkjet printhead has a plurality of thin film resistors provided on a substrate, e.g. a silicon substrate. A nozzle plate and barrier layer are provided on the substrate and define the firing chambers about each of the resistors. Alternatively, the nozzle plate and barrier layer are combined in a single layer. Flow of a current or a xe2x80x9cfire signalxe2x80x9d through a resistor causes fluid, e.g., ink, in the corresponding firing chamber to be heated and expelled through the appropriate nozzle.
Fluid is typically delivered to the firing chamber through a feed slot that is machined in the substrate. The substrate usually has a rectangular shape, with the slot disposed therein. Resistors are typically arranged in rows located on both sides of the slot. In an inkjet printhead, the width of the print swath achieved by one pass of a printhead is approximately equal to the length of the resistor rows, which in turn is approximately equal to the length of the slot.
The feed slot tends to reduce the substrate strength, leading to increased die chipping and cracking defects. Also, air bubbles can collect and grow in the feed slot, leading to fluid flow issues and nozzle starvation.